[Small dolphin phone] Taishan send 4G Internet small phone

# 1 Display  # 2 Project Description A smart "mobile phone" based on Taishan pie, which can realize voice chat, 4G Internet access, play games, and shoot videos, the shell is 3D printed, and the back cover is designed with a Lichuang color panel. # 3 Video Presentation [I made a "mobile phone" for 100 yuan, can I shoot videos? Playing Genshin Impact? Bilibili _bilibili](https://www.bilibili.com/video/BV13i421C72x) # 4 Project Features 1. Compatible with 3.1-inch touch screen. 2. Reserved EC20 4G module mini PCIE interface, SIM card. 3. On-board microphone. 4. Reserved speakers and RTC interfaces. 5. Onboard CH343G TYPE-C DEBUG SERIAL PORT. 6. Onboard CH224K PD decoy chip with 12V output. # 5 Schematic Description ## 1.POWER The EC20 module consumes a lot of power, and the 4G module has an independent power supply output. The power supply switch of the 4G module is controlled by the 4G_PWREN_H pin, GPIO0 PA5, and the pin can be set low when 4G is not needed to save power supply.  Due to the excessive power supply current of the 4G module, the use of the computer USB function will cause the Taishan Pi system to restart indefinitely, so it is equipped with a PD decoy circuit. Use the mobile phone power adapter and PD power bank to input through the TYPE-C pin, and the CH224K chip tricks the PD12V power supply output to supply power to the system. Here CFG1, CFG2 and CFG3 pins are the output pins of the control system, and 24K resistors are added to CFG1 to make the PD output 12V, please refer to the CH224K chip manual for the detailed configuration process.  The backlight directly uses Taishan pie power supply will make the screen hot,Here a power supply IC is used for power supply,PWM output pin is the GPIO0_C5 of the expansion port (need to be changed in the device tree).  ## 2.EXP The expansion pins, in which only the USB interface and the GPIO0 PA5 pin are used, are mainly used to communicate with the 4G module. The USB interface communicates with the EC20 USB, and the GPIO0 PA5 pin is turned on at a high level and turned off at a low level.  The expansion board is also connected to Taishan Pie through a 10mm thimble to provide 12V, serial port, microphone, and speaker. ## 3.PCIE EC20 circuit, refer to Taishanpai network expansion board, because the fixed hole of the EC20 module is blocked by the touch screen cable, the EC20 module is fixed with CN6 here.  ## 4.LCD Circuit reference [1], mainly MIPI and touch circuit transitions. ## 5.AUDIO/DEBUG Provide CH343G serial port to TTL, microphone, audio and RTC.  # 6 Circuit Diagram Description The circuit diagram is annotated as follows.  # 7 Enclosures and panels The shell is 3D printed using 9000R material, and the printed documents are attached here. Because the bottom cover of the design is too thin to be 3D printed,The bottom cover V2.STL does not actually need to be printed!!Here through the transparent and colored acrylic panel superimposed, the transparent acrylic back cover can be matched with the shell card slot, the color acrylic sheet has glue on the back, can be glued on top of the transparent acrylic cover.   # 8 Assembly Process Assembly reference video[Small mobile phone DIY assembly Taishan pi](https://www.bilibili.com/video/BV1DU411o7R5)  # 9 Using References For detailed tutorials, please refer to the development board manual. * Lckfb[[Lc Taishan Pi RK3566] Development Board - Feishu Docs (feishu.cn).](https://lceda001.feishu.cn/wiki/IJtRwVu5kiylHykl3RJcQ8ANncY) * Mobile phone production process[[Fat Girl Mobile] Practical Project Information - Feishu Cloud Document (feishu.cn).](https://lceda001.feishu.cn/wiki/M1DVwL6HgihWzlkKgmucPbDbnG4) * Android System Compilation[[Android]System SDK Compilation - Feishu Cloud Document (feishu.cn).](https://lceda001.feishu.cn/wiki/CF38wAxs1irt0zkPxOXcWJuCnDd) * System Image Burning[[Download]Image Burning - Feishu Cloud Docs (feishu.cn)](https://lceda001.feishu.cn/wiki/GXdUwyGlZimkHHkpdMmcusSPnrf) # 10 Software Debugging Code Patch Download: [Zhigo Xiaobai/TSPiPhoneEXT - Gitee.com](https://gitee.com/faltering_and_small_white/tspi-phone-ext/tree/master) # 11 Material Reference | Material | Model | Link (for reference only) | | :------- | -------------------- | ------------------------------------------------ | | 4G module | EC20 | [https://m.tb.cn/h.g0cwnmI2zW8jL4I?tk=se1zWrEOK22](https://m.tb.cn/h.g0cwnmI2zW8jL4I?tk=se1zWrEOK22) | | Loudspeaker | 2209 | [https://m.tb.cn/h.gZqOZijCgpquogw?tk=7byiWrEmmut](https://m.tb.cn/h.gZqOZijCgpquogw?tk=7byiWrEmmut) | | Touch the cable | 6P 6 cm on the same side 0.5mm | [https://m.tb.cn/h.g0vaMhBpkwiYjat?tk=QEFUWrEmfey](https://m.tb.cn/h.g0vaMhBpkwiYjat?tk=QEFUWrEmfey) | | Screen cables | 31P 6 cm Same side 0.3mm | [https://m.tb.cn/h.gZqMBM7sMdxqR3q?tk=xne8WrEM3YR](https://m.tb.cn/h.gZqMBM7sMdxqR3q?tk=xne8WrEM3YR) | | Extended cables | 39P 6cm Same side 0.3mm| [https://m.tb.cn/h.gZqMBM7sMdxqR3q?tk=xne8WrEM3YR](https://m.tb.cn/h.gZqMBM7sMdxqR3q?tk=xne8WrEM3YR) | | Debug the serial port | CH343G SOP-16 | [https://m.tb.cn/h.gZqM703vpLD9gS9?tk=a7Y2WrEMiIX](https://m.tb.cn/h.gZqM703vpLD9gS9?tk=a7Y2WrEMiIX) | | Camera | OV5695 | [https://m.tb.cn/h.g1F0lHoYcpuq610?tk=YsL9WGhYOwF](https://m.tb.cn/h.g1F0lHoYcpuq610?tk=YsL9WGhYOwF) | | Surface-mounted copper pillars | M2X4X2 | [https://m.tb.cn/h.gXifnTuiHjfXejc?tk=pEcWWGh14U9](https://m.tb.cn/h.gXifnTuiHjfXejc?tk=pEcWWGh14U9) | | Surface-mounted copper pillars | M2.5X4.5X9 | [https://m.tb.cn/h.gcqPH4JLCWgwukr?tk=dqGtWGhYWLl](https://m.tb.cn/h.gcqPH4JLCWgwukr?tk=dqGtWGhYWLl) | | Copper pillars | M2.5X9+6 | [https://m.tb.cn/h.g1F05FI4s6vq4hM?tk=uKEAWGhbNzi](https://m.tb.cn/h.g1F05FI4s6vq4hM?tk=uKEAWGhbNzi) | | Screw | BM2.5*5 | [https://m.tb.cn/h.gcqOhk6OtbETlWD?tk=Q4VYWGh1BGy](https://m.tb.cn/h.gcqOhk6OtbETlWD?tk=Q4VYWGh1BGy) | | Screw | CM2*5 head diameter 5 | [https://m.tb.cn/h.g1F0Og2GhkunkTD?tk=YKR4WGhbruw](https://m.tb.cn/h.g1F0Og2GhkunkTD?tk=YKR4WGhbruw) | | Other | Refer to the BOM | | # 12 Photo Gallery   # 13 Release Update Notes ## 2024-4-21 V2 Optimized the layout of the screen interface ## 2024-5-28 V3 Added screen backlight circuit IC to optimize the problem of screen backlight heating # Project References [1] [Taishan Pi 3.1 inch screen expansion board - integrated power supply, audio, serial port, RTC - JLC EDA open source hardware platform (oshwhub.com).](https://oshwhub.com/fengmoxi/tai-shan-pai-3-1-cun-ping-mu-kuo-zhan-ban) [2] LC Taishanpai development board 39Pin_Hub2.0_ Ethernet expansion board.